On Holiday - Calcium Reactor has run out of CO2 - how long can my tank last?

[Dukereefnz]

On Holiday - Calcium Reactor has run out of CO2 - how long can my tank last?
The alarm was going so the neighbor who is feeding our dogs turned it off.

Today is Wednesday, it will be 5 days before I can get it running again....
How long can my tank handle no calcium addition...

I have a lot of coral etc.. tank is 200G.
Nothing I can do about it, except drive home 4hrs each way... plus 2 hrs to get CO2.
Today is Thursday - I could drive 4hours home, 1hrs each way fr CO2, and 4hrs back to holiday.
Then have Friday, only to drive home Saturday. Cant get CO2 until Monday as it is closed Sunday.

What should I do?

 

[braaap]

See if your neighbor can get a calcium additive to manually dose.

 

[Dukereefnz]

Not going to happen, we live in the country, and my neighbor is old.
I saw that the bottle was low, 5min before we left.... what a pain!

 

[Randy Holmes-Farley]

The calcium is no concern anyway. Alk will drop and limit consumption before calcium declines much.

My expectation is it will eventually drop down to maybe the 6 dKH range and stop there, maybe a bit lower.

Where do you normally keep alk?

My best guess is that it will be OK, and I'd just slowly raise it back to your target when you are home. Don't jump it right back. Corals may adjust to the lower alk and won't like a jump.